At first glance this change to "Racing" spec tires is a good thing. Bikes are going faster, etc, etc, BUT! Unless some manufacturer steps up and starts making LSR tires this rule change creates problems with enforcement and mandates tires that could actually lead to more tire problems and accidents. Please consider -
What is a “Racing” tire and what guidelines will the techs use to enforce the rule?
• Are DOT tires allowed or is the new rule interpreted as specifying pure, non DOT, racing tires?
• DOT approved tires give you a speed (and load) rating clearly marked on the tire and can be easily checked by tech.
• Non DOT tires aren’t covered by the same rules. No clear markings as there aren’t any load or speed ratings to be tested to!
• There are many true “Racing” tires that meet the letter of the rule that are not fit for the speeds or loads encountered in LSR. How is the tech expected to sign off or veto a particular example?
• If it’s interpreted as pure, non DOT, racing tires what is tech supposed to check for?
• What makes it a “Racing” tire? The fact it doesn’t include a DOT approval? Lawn mower tires don’t have a DOT stamp either but I wouldn’t run one. I’ve seen items, including tires, specified in literature as “Racing” when in reality they are no more than cheap imported junk I wouldn’t trust on any motorcycle much less a 600hp Hayabusa.
Again, What is a tech supposed to check for? The answers may or may not remove the ability of most racers from competing in a class covered by the new rule.
Thoughts on the “It’s a racing tire, it must be better” view that seems to have led to the new rule.
DOT approved tires are tested at their specified load rating and at their specified speed on a test machine for at least 10 minutes.
• A tires biggest enemy is heat. Problems come when, at speed, a tire accumulates heat faster than it can disapate it. Tires flex. At speed they’re flexing more so they generate more heat. More speed, more heat. More speed also gives you more Centrifical force which by itself doesn’t destroy the tire but the growth it leads to can create even more flex before and after the contact patch so indirectly it adds to the problem. Shaving tires lets it disapate heat faster and helps decrease its weight for less flex and heat. Higher tire pressures help push a tire closer to it’s growth diameter so you get less flex and less heat build up.
• I checked specs on several current high performance tires like Hayabusa be required to run under the old rule. All had a load rating of 75 which specifies a 853 pound load. When was the last time you saw an 853 pound race bike? A superbike is probably one of the heaviest current race classes and they come in significantly under 400 pounds. An LSR Hayabusa might have some weight removed but then they add up to ?? 100 pounds for traction. That means a Hayabusa weighs more than double what a “Racing” tire was designed for. More load, more heat, more problems!
• Except for LSR, essentially all other racing takes place on a closed course where top speed counted in seconds. Racing tires are not subjected to the extended high speed s of a LSR run. Longer high speed pass, more heat, more problems!
• The old rule states, among other things, harder compound provide the best results. When was the last time you saw a harder compound racing tire?
• With racing tires an engineer knows it will be run under the conditions it’s designed for with the proper inflation, etc. With Road tires engineers are faced with much larger safety margins in that they know a tire can and will be subjected to ridiculous real world conditions, under inflation, incredibly hot road tempetures, etc, etc.
I’d have to say a current, properly prepared, high speed rated, touring or sport/touring tire could be, in reality, safer in the Land Speed Racing arena.
• It’s test proven to have the ability to handle the heavier loads that more correctly model the bikes attaining these speeds.
• It’s test proven to have the ability to handle high speeds for longer periods of time, that more correctly model the bikes attaining these speeds.
In general the bikes in question have an incredible safety record. Consider how many runs John Noonan and Jason McVicar have between them. They (and others ) are pushing the envelope far above anything that could have been even considered just a few years ago and yet tire failures are very rare.
I hope, if this rule change stays in place! That record continues.
Thanks
Billy
